added warning about inconsistent context to Metis;
it makes more sense here than in Sledgehammer, because Sledgehammer is unsound and there's no point in having people panicking about the consistency of their context when their context is in fact consistent
\documentclass[10pt,a4paper,twoside]{article}
\usepackage{graphicx}
\usepackage{latexsym,theorem}
\usepackage{isabelle,isabellesym}
\usepackage{pdfsetup}\urlstyle{rm}
\begin{document}
\pagestyle{headings}
\pagenumbering{arabic}
\title{Verification of The SET Protocol}
\author{Giampaolo Bella, Fabio Massacci, Lawrence C. Paulson et al.}
\maketitle
\tableofcontents
\begin{center}
\includegraphics[scale=0.5]{session_graph}
\end{center}
\newpage
\parindent 0pt\parskip 0.5ex
\input{session}
\end{document}